Nuhanovic, Mirza, et al. “The Effectiveness of Natural and Synthetic Antioxidant Additives on the Oxidation Stability of Biodiesel Synthesized from Fresh and Waste Sunflower Oilesized from Fresh and Waste Sunflower Oil”. Orbital: The Electronic Journal of Chemistry, vol. 10, no. 7, Dec. 2018, pp. 535-42, https://periodicos.ufms.br/index.php/orbital/article/view/16034.